904 Transmission Stopped Going Into Gear

Ok so I was just being a dummy and forgot to remove the kickdown piston, it was in the case.:rolleyes:

On to my next questions for the counsel:

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Does the pin on my output shaft look ok? Looks a bit rough around the edges like it was broken... is it replaceable?

Seen way worse that reused without issue, as that pin just basically aligns the gear train shafts at their meeting point.
The planetary gear set takes care of the aligning once it's back together
The thrust washer that goes on that pin is important though, and you may even need a different one for endplay concerns but can cross that bridge when you get to it.


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These are the sealing rings that are on my governor assembly. Is it supposed to be a combination of 1 normal sealing ring and 1"interlocking" sealing ring? Also, that top normal sealing ring looks awful big but thats the one that was on it....

Usually they are both the same, but someone was in that trans before for sure.
It really wouldn't make any difference though since both type rings doo the same job anyway.
(Factory was two open ended rings, that you had to be careful not to snap off when reassembling):D

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The sealing ring on my accumulator broke in half when I tried to remove it. My rebuild kit did not come with a new steel one, so Im looking for a source for a new one. Might just get a variety pack if I can find it.

Teflon rings are more commonly in newer transmissions, but if done correctly they can also be used in older transmissions.
I like the metal rings myself, but I do have to admit the Teflons do work even though they look like they would leak fluid badly.:D
Over bending the ends a little and heavily lubing then in place making sure the ends don't get cut off on assembly is the main PIA about Teflon.
They make rubber D rings as a replacement for the metal ring, because the rubber rings seals better.
If the Teflon ring fits right there shouldn't be a problem, but a better seal will mean better holding pressures on the second gear (kickdown) band.
Teflon wears on the metal surfaces more that steel rings also believe it or not, but I have to admit I have used them (and specifically as on an accumulator piston)



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On the topic of sealing rings, what is this? It is flexible plastic (teflon?) and has tapered ends (scarf cut?) that mate together. They came in various sizes in my rebuild kit. The internet is telling me they are also sealing rings. Are they meant to replace steel sealing rings (both simple and interlocking steel rings)? Should I use one on my accumulator?

So there are three types of sealing rings:
-standard steel
-interlocking steel
-plastic bendy (teflon?) with tapered ends as in the pic

Yep, "scarf cut" it is.
I think I covered the main stuff about them up there.


I have many plastic rings in my rebuild and not many steel rings. Should I be replacing all steels with the plastic scarf cut ones?

I replied within your post for simplicity.